Pyridyl substituted ketones



Patented Dec. 18, 1951 Albert -M.liftord, Stow, Ohio, assignor to Wingfoot Corporation,. Akron, f6lno-,- arcarporation of Delaware No Drawing. Application- Jilly 13,1946,

Serial No. 6253,4'1'3 7 Claims. (CIvZw -QW This invention relates to a new class of substituted pyridines and to a method for their preparation from readily available "raw materials. More specifically, the inventionrelatesto -compounds prepared by the addition of vinyl pyridine with 'ke'tones. h

In accordance with'thi's invention compounds containing carbonyl groups attached directly to acarbon atom in each of two organic radicals maybe reacted with 2-v'inyl pyridine 'to'p'roduc'e 2-(2'-pyridyl)' ethyl ketones compounds previously' unknown. The new substances are definite chemical compounds, the result of addition between equimolecular proportionsof ketone and vinyl pyridine.

The preferred ketones for the practice of this invention are those having, an alpha carbon. atom "carrying at least one hydrogen atom and having in which R is a hydrocarbonradical, a radical containing a sulfur atom, or a radical containingan oxygen atom, and B" may be either hydrogen or a radical'of the B group. The R radicals may be either the same or different radicals. The R, hydrocarbon radicals include the alkyl radicals, such as. methyl, ethyl, butyl, octyl, dodecyl and cetyl, the aryl radicals, such as phenyl and naphthyl, the aralkyl radicals, such as benzyl, phenylethyl, and naphthylethyl, the alkaryl radicals, such as. tolyl, ethylphenyl, and methyinaphthyl, and the cycloaliphatic radicals, such as cyclohexyl and cyclopentyl. In addition to hydrocarbons, R radicals in the above structural formula may contain one or more oxygen atoms, or sulfur atoms which are substituted for CH2 groups including the alkoxyalkyl radicals, such as methoxyethyl and ethoxybutyl, the aryloxy' alkyl' radicals, such as phenoxyethyl and naphthyloxy methyl, the alkoxyaryl radicals, such as methoxy phenyl and ethoXynaphthyl, the aryloxyarylv radicals suchaas phenoxyphenyl, and phenoxynaphthyl, and the alkoxy or aroxy-substituted cycloal'iphatic radicals, such as methoxy cyclohexyl and phenoxy cyclopentyl and the corresponding thiahydro- :carbon radicals.

Other useful ketones are those of theistructural formula in which ..R' and one of the R radicals represent a single divalent aliphatic hydrocarbon radical, radicals containing-oxygen or sulfur, such as cyclopentanone, cyclobutanone, cyclohexanone, cyclopentenone, 3 -thia-cyc1ohexanone,

CHrCHz CHPCg a-oxa-cyclohexanone,

I Olga-0E2, -o=c o CH2-O7 and the derivatives of other cyclic ketones containing oxygen or sulfur atoms. Still other useful. .ketones are those which include an ester linkage in one. or more of the R and R radicals, for example ethyl aceto acetate, methyl pyruvate, ethyl levulate, methylv mesitonate and h-omologues so 7 Generally the useful ketones may be defined by thev general formula:

R .0 R en-L B w'lierei'n R is a radical" of the group consisting j-l2:hours. react-ion: in the presence of a polymerization. in-

--phenylene-diami ne.

R visvaradical of thegroup consisting of hydrogemandR R is a monovalent radical of the group. consisting, of hydrocarbon, radicals conoxygen or sulfur atoms, and R is a divalent radical of the group consisting of hydrocarbon, and. radicals containing oxygen or sulfur atoms.

. Thecondensation or addition between 2-vinyl pyridine and the ketones is effected by mixing thev reactants and heating them at reflux tem- :peratu-res. Generally, any period of time may be used but preferred operations require two to Usually, it is desirable to conduct the hibitor to prevent the vinyl pyridine from becoming. polymerized during the reaction. The additionofwa-ketone to vinyl pyridine is aidedby an alkaline catalyst, such as caustic soda, sodium alcoholate or trimethyi benzyl ammonium hydroxide; Suitable polymerization inhibitors are hydroquinone, resorcinol and diphenyl-para- The vinyl pyridine, the ketone and the polymerization inhibitor are -usually charged into a'glass-lined reactor provided with a water-cooled reflux condenser. When-the reaction is complete the reaction mass may be transferred to a. separate distillation flask, or tower, or the distillation may be effected from the reaction flask by replacing the reflux condenser with a suitable receiver. The majority of the reaction products can be separated by fractional distillation at reduced pressures, but some require other methods of separation, such as fractional crystallization from solutions in suitable solvents.

The new chemical compounds are useful as plasticizers, as intermediates for the preparation of industrial and pharmaceutical chemicals.

Further details of the practice of this inven tion are set forth with respect to the following specific examples.

Example 1 A glass reaction vessel provided with aj' cooled reflux condenser was charged with 105' grams of 2-vinyl pyridine, 144 grams of methylethylketone and 3 cc. of a 40 percent summon of trimethyl benzyl ammonium hydroxide and heated at the reflux temperature for '8, hours The reaction mass was transferred to a suitable vacuum distillation flask and the fraction boiling between 150 and 155 C. at 22 mm. was separated. This product was' identified as a condensation product of equi'molecular proportions of vinyl pyridine and methylethylketone.

Erample 2 Using the apparatus and procedure described in the preceding example, 105 grams of 2-vinyl pyridine were condensed with 147 grams of cyclohexanone in the presence of 2 grams of tertiary butyl catechol and 3 cc. of a 40 percent solution of trimethylbenzyl ammonium hydroxide by refluxing for a 10 hourperiod: The distillation of the reaction mass yielded a substantial proportion of the condensation product of equimolar proportions of vinyl pyridine and cyclohexanone.

Example 3 Using the apparatus and procedure described ketones, alkaryl ketones, cycloaliph'atic ketofis, alkoxyalkylketones, aryloxyalkyl ketones, a1- koxyaryl 'ketones, aryloxyaryl ketones, alkoxysubstituted cycloaliphatic ketones, aroxy-substituted cycloaliphatic ketones, and unsubstituted satu rated 6 ,membered cycloalkyl ketones in which a' single ring 41-12- group is replaced by the member, o f;the group consisting of oxygen rand-sulphur...

2. An unpolymerized ketone having the gener .iomu

4; The method of preparing a 2-(pyridyl) ethyl ketone which comprises heating, in the presence of an alkaline catalyst and an inhibitor of polymerization for 2-viny1 pyridine, cy-

, 'clohexanone with 2 viny1 pyridine, and separating in Example 1, grams of 2-vinyl pyridine and grams of the ethyl ester of acetoacetic acid were condensed in the presence of 3 cc. of a 40 percent solution of trimethylbenzyl ammonium hydroxide by heating on a steam bath for 10 hours, followed by heating at reflux temperatures for 3 hours. The distillation yielded a substantial proportion of a material boiling at 152-155" C. at 2 mm. pressure. The compound separated was identified as the equimolecular condensation product of acetoacetic ethyl ester and vinyl pyridine.

Condensation products of 2-vinyl pyridine and acetone, methyl isobutyl ketone, diethyl ketone, methyl propyl ketone, cyclopentanone, acetophenone and propriophenone may similarly be prepared.

'- Although the invention has-been described with respect to specific modifications thereof, it is not intended that the details set forth-shall be construed as limitations upon the scope of the invention except to the extent incorporated in the following claims. I

I claim: 7

1. The method of preparing 2 (2 -pyridyl) the resulting unpolymerized product.

5. The method of preparing a 2-(2-pyridyl) ethyl ketone which comprises heating, in the presence of an alkaline catalyst and an inhibitor of polymerization for 2-vinyl pyridine, ethyl ,acetoacetic acid with 2-vinyl pyridine, and separating the resulting unpolymerized product.

6. An unpolymerized ketone having the formula O C Hz'CHa C H21 3 C 2H ethyl ketoneswhich comprises heating, in the presence of an alkaline catalyst and an inhibitor of polymerization for 2-viny1 pyridineya ketone 'having an alpha carbon atom carrying atleast one hydrogen atom with 2-vinyl pyridine, and separating the resulting unpolymerized product, the ketone being selected from the group consisting of alkyl ketones, aryl ketones, -aralkyl H2 "H2 7 cz ALBERT M. CLIFFORD.

REFERENCES CITED The following references are of record in the file of this patent:

V uprr zo STATES PATENTS Number Name Date 1,937,063 Meisenburg et al. Nov. 28, 1933 2,469,295 Meier May 3, 1949 IOTHER REFERENCES sidewicksz" Organic Chemistry of, Nitrogen, new e i pn- 522-528. 

1. THE METHOD OF PREPARING 2 - (2 - PYRIDYL) ETHYL KETONES WHICH COMPRISES HEATING, IN THE PRESENCE OF AN ALKALINE CATALYST AND AN INHIBITOR OF POLYMERIZATION FOR 2-VINYL PYRIDINE, A KETONE HAVING AN ALPHA CARBON ATOM CARRYING AT LEAST ONE HYDROGEN ATOM WITH 2-VINYL PYRIDINE, AND SEPARATING THE RESULTING UNPOLYMERIZED PRODUCT, THE KETONE BEING SELECTED FROM THE GROUP CONSISTING OF ALKYL KETONES, ARYL KETONES, ARALKYL KETONES, ALKARYL KETONES, CYCLOALIPHATIC KETONES, ALKOXYALKYALKETONES, ARYLOXAYALKYL KETONES, ALKOXYARYL KETONES, ARYLOXYARYL KETONES, ALKALKYL SUBSTITUTED CYCLOALIPHATIC KETONES, AROXY-SUBSTITUTED CYCLOALIPHTIC KETONES, AND UNSUBSTITUTED SATURATED 6 MEMBERED CYCLOALKYL KETONES IN WHICH A SINGLE RING -CH2-GROUP IS REPLEACED BY THE MEMBER OF THE GROUP CONSISTING OF OXYGEN AND SULPHUR. 